Crowd for boom structures



Dec. 8, 1942. H E, W NSON 2,304,486

CROWD FOR BOOM STRUCTURES Filed July 23, 1941 2 Sheets-Sheet 1 m dlwmDec. 8,1942. H, SON 2,304,486

CROWD FOR BOOM STRUCTURES Filed July 23, 194; 2 Sheets-Sheet 2 it willpenetrate Patented Dec. 8, 1942 CROWD FQR BOOM STRUCTURES Hilbert E.Swanson, Milwaukee, Wis., assignor to Universal Unit Power ShovelCorporation, West Allis, Wis a-c'or-poration of Delaware ApplicationJuly 23, 1941, Serial No. 403,619

5 Claims.

This invention relates in general to boom structures and hasmoreparticular reference to a crowding belt assembly therefor that isself-adjusting to expedite adjustment of a live boom about its pivotalfooting.

The invention is especially useful in power shovel installationsof thecharacter employing a live boom with a dipper stick having a scoop ordipper upon one end. In these installations the dipper stick isconventionally longitudinally adjustable in a mount therefor pivotallysecured to an intermediate section of the boom. Boom hoisting cablesnormally support the boom in a selectively inclined position, and othercables passing over pulleys at the free end of the boom are connectedwith the dipper for drawing it outwardly from the boom footing with ascooping action while pivoting the dipper stick about the axis in itspivotal mounting. During such scooping action the dipper iscrowdeddownwardly so or slide under material being loaded thereinto.This crowding of the dipper is effected by a crowding belt or chainportion connected with an upper part of the dipper stick and extendingdownwardly along such stick to and about a belt guide means in the formof a sprocket idler journalled coaxially with the dipper stick mounting,the stick and hence the dipper being urged downwardly when a tensileforce is exerted upon apart of the belt extending beyond said belt guidemeans. A retrieving belt portion, which is connected with the dipperstick at a point below the belt guide means, extends upwardly and aboutsaid guide means wherefore exertion of sufiicient tensile force upon thepart of this second belt portion beyond the belt guide means willretract the dipper stick endwise upwardly in its mounting and thus liftthe dipper. Usually these two belt portions are end portions of a singlebelt of which an intermediate portion is wrapped about a reversing rotorconstituting a driver therefor, so that when this rotor is rotated inone direction the aforesaid crowding belt portion will be wound towardand upon the rotor for crowding the dipper while the retrieving portionis payed outto prevent its trammeling of the crowding action, and sothat when the rotor is rotated in the opposite direction the retrievingportion will be wound toward and upon the rotor for raising the dipperwhile the crowdportion is payed out to avoid trammeling the dipperraising action. It follows that when the reversing drum is held fast thecrowding and retrieving belt portions necessarily secure the dipperstick against endwise movement in either direction.

In these prior structures the crowding and retrieving belt portions haveextended as free flights directly from the guide means on the boom tothe reversing rotor and both above the pivotal boom footing.Consequently if the boom should be lowered said flights would first haveto be lengthened to permit this adjustment, and, on the other hand, ifthe boom should be raised said flights would have to be shortened topreserve this proper tautness. Changes in the length of the belt flightshas involved the inconvenient step of loosening one of the belt portionsat its anchorage on the dipper stick to readjust the overall beltlength, wherefore changes in boom elevation have been annoying time-con:suming tasks.

A principal object of the invention is the provision of an improved boomstructure employing .a crowd beltoperable to adjust a work member suchas a dipper stick in opposite directions, but requiring no auxiliaryadjustment pursuant to pivotal movement of the boom upon its footing.

Another important object'of the invention is i the provision of a liveboom structure including crowd and retrieving belt portions havingrespective flights leading from belt guide means at an intermediate partof theboom to a reversing means for pulling in either of said flightswhile paying out the other, and also including additional belt guidemeans adjacently to the boom at its footing and over which said flightsrespectively pass before reaching said reversing means.

A further important object of the invention is the provision of a liveboom structure having additional belt guide means which are spacedtransversely of the boom and are upon substantially opposite sides ofthe pivotal axis for the boom at its footing,

A still further object of this invention is the provision of j a liveboom structure wherein the belt guide means are mounted upon oppositesides of the boom and upon substantially opposite sides of the axis inits pivotal footing.

Numerous other objects and advantages of the invention will be apparentas it is better understood from the following description, which, whentaken in connection with the accompanying drawings, discloses apreferred embodiment thereof.

. In the drawings,

Figure 1 is a perspective side view of a power shovel machine embodyinga preferred form of the invention;

Fig. 2 is a fragmentary diagrammatic side view .front edge.

of the footing end of the boom shown in Fig. 1, together with belts andbelt guide means in the form of sprocket wheels arranged in accordancewith the present invention;

Fig. 3 is a view like Fig. 2 illustrating the relative position of theparts when the boom occupies a different angle of inclination;

Fig. 4 is also a view like Fig 2 but illustrating the parts when theboom is in the horizontal;

Fig. 5 is a sectional View taken through the reversing drive shaftassembly as indicated on the line 5-5 in Fig. 1;

Fig. 6 is a sectional view taken on the line 8-6 of Fig. 1 and showingan idler assembly for the rack-in or retrieving portion of the crowdingbelt; a

Fig. 7 is a sectional view illustrating a shipper shaft assembly, theview being taken on the line 1-1 of Fig. 1; and

Fig. 8 is an enlarged view partly in section of a yieldable anchoragefor the rack-in end of the crowding belt, this view being taken asgenerally as indicated by the line B--8 in Fig. 1.

Referring to the drawings, the invention is shown in association with amobile power shovel machine mounted upon crawlers I I, one of which isshown in Fig. 1, at opposite sides of a frame (not shown) on which thereis mounted a turntable l2 provided with the usual cab I3 which enclosesa power plant, various parts driven thereby and controls therefor whichmanipulatable by an operator. A live boom l4 has a footing portion I5pivotally mounted upon a footing pin [8 carried in a pair ofspaced-apart upright standards H and I8 upon the turntable l2 adjacentlyto its The boom I4 is of the beam type and hollow for minimizing itsweight. The outer end of the boom is supported by several flight of ahoist cable [9 extending between a pulley assembly generally designated2! upon the outer end of said boom and a second pulley assembly 22fastened upon a mount 23 carried by the turntable l2. A

drum 24 is adapted to be driven in one direction for winding in thecable IQ for hoisting the boom and for rotation in the oppositedirection for paying out the cable and permitting the boom to lower.

A socket 25 at an intermediate section of the boom receives a workmember in the form of a dipper stick 2E and also a pivotal mountingmember 21 in which the dipper stick is axially movable. Said mountingmember 21 is pivotally connected with the boom I4 by means of a shaft28; see Figs. 1 and '7. Pivotal movement of the dipper stick 26 and ofits pivotally supported mounting member 21 is accomplished by a dippercable 29 of which a section passes over one of the pulleys in the pulleyassembly 2! and extends backwardly to adrum 3| in the cab 13. It will beseen that when the drum 3| is driven counter-clockwise, as viewed inFig. 1, the cable 29 in acting upon a pulley 32 connected with a dipper33 upon the lower end of the dipper stick will cause the latter to pivotcounter-clockwise while the dipper 33 is advanced outwardly and upwardlywith a scooping action.

Axial movement of the dipper stick 28 is accomplished by means of acrowd belt 34 which in the present instance is a chain, although it maybe a smooth belt or cable if desired. Upward or retrieving movement ofthe dipper'stick is effected by a rack-in or retrieving belt portion 35of which the free end is connected with a lower portion of the dipperstick by a yieldable anchorage device 36shown'in detail in Fig. 8. Saidanchorage delit vice includes a flanged stud 30 secured to the dipperstick in a suitable manner and provided with an aperture 3! in which abolt 38 is reciprocally mounted. The upper end of the bolt 38 isprovided with a transversely apertured head 39 facilitating attachmenttherewith of the lower link of the belt portion 35 by means of a pin 4!.An annular yieldable cushion member 42 which may be of rubber surroundsa shank portion of the bolt 38 immediately below the flanged portion ofthe stud 30. A metal sleeve 43 is disposed between the cushion member 42and the bolt 38 while a cylindrical confining sleeve 44 is disposedabout the outer periphery of said member 42. The lower end of the sleeve43 projects endwise below the member 42 where it receives a washer 45which is held in place by a nut 48 turned upon the lower threaded end ofsaid bolt 38. It will be seen that force applied upwardly to the bolt 38will cause the washer 45 to press endwise against the cushion member 42which will yield slightly under the force and thereby provide ayieldable anchorage for the lower end of the belt portion 35.

Said belt portion 35 extends upwardly from its lower end to and about abelt guide means 41 which in the present instance consists of aplurality of idler sprockets 48, 49 and 5! in the shipper shaft assemblyshown in detail in Fig. '7. These idler sprockets are carried rotativelyupon the shipper shaft 28 where they'ride upon bushings 52, 53 and 55.It will also be seen in Fig. '7 that the shipper shaft is heldnon-rotatively in bushings 55 therefor in the boom [4 by means of setscrews 58, and that side plates 5'! and 58 of the mounting member 2'!for the dipper stick are journalled upon said shipper shaft. The spacebetween transverse plates 59 and El is that in which the dipper stick isreciprocally disposed.

From the belt guide means 4! the retrieving belt portion 35 extendsbackwardly as a. flight beneath an additional belt guide means 82 and toand about a reversing drive means 83. The single belt portion 35 isjoined to and between the components of a double belt portion 54 asindicated at 65. When the belt portions consist of chains theoverlapping sections at 85 are connected by using long pins common toeach of the chain portions and for connecting their links together.

The double belt portion 84, for the main part, constitutes the crowdportion of the belt for forcing the dipper stick downwardly. It isconnected with the dipper stick near its upper end and from this pointextends downwardly to and about the belt guide means 41' in the oppositedirection to which the belt portion 35 extends about such belt guidemeans, the components of this belt portion. passing upon either side ofthe belt portion 35 and about the sprockets 48 and 5| as shown in Figs.1 and 7. From the belt guide means i! the crowd belt portion 84 extendsdownwardly and forwardly as a flight about a second additional beltguide means 36 and over an idler belt guide means 6'! to and about thereversing drive means 83.

Referring to Fig. 6 the belt guide means 62 will be seen to include aplurality of sprocket idlers 88, 8!! and H integral witha sleeve 12journalled upon a shaft d3 of which the ends are secured in standards'14 and i5 projecting upwardly from the footing end of the boom 84. Thebelt portion is shown. meshed with the idler sprocket 58 although thesprockets 88 and H are adapted to mesh with the components of the doublebelt portion 64 incident to rotation of the reversing drive means 63sufiiciently action.

clockwise as viewed in Fig. 1 to displace the double belt portion intoregistry withithe guide means 62.

In Fig. the reversing drive means will be seen to include threedriversprockets '16, TI and 18, integral with a hub member 19 which is splinedat 8| to a ccuntershaft 82. Saidcountershaftis journalled uponroller-bearing :units 83 and 84 in respective wa1ls'85 and 8.6 of agearbox. Driving force for rotating the counter- "shaft 82 and hence thesprockets 1B, 1111 and 18 :is received througha :gear 81 splined to thecounter-shaft at 88. Means (not shown) is provided for selectivelydriving the gearill in either direction. The axial spacing of thesprockets for advancing the belt portion 35 into registry with saidsprocket I 1.

The idler guide means 6! also comprises three axially spacedsprockets ofwhich the outermost mesh with the components of the double belt portion64 and of whichthe intermediate sprocket is-ada-pted to mesh with theretrieving beltportion 35. These sprockets of the idler belt guide means61 are designated 89, 9| and "92.

The second of the additional .guide means, .66, at the foot of the boom.14 is constructed similarlyto the belt guide means 62 shown in detailin Fig.6, but the sprockets '93, 54 and 95 thereof,

corresponding to the sprockets 68, 68 andpfil of the belt guide means62, are supported upon the "boom beneath the pivotal axis in thefooting. pin

l6 instead of above this axis. Such relativeposition ofthe additionalbelt guide means 62 and fiii with respect to the footing pin I6 isillustrated in Figs. 2, 3 and 4.

Manually controlled clutch means (not shown) is provided in the cab l3for enabling an operator to selectively connect the reversing drivemeans 63 with the power plant (not shown) for rotation in eitherdirection. When the drive means is thus connected for rotatingcounterclockwise the retrieving belt portion 35 will be drawn inwardlyfor raising the dipper stick while the crowder portion 64 of the beltwill be payed out to permit such upward movement of the dipper stick.Clockwise rotation of the reversing means 63 will obviously cause thedipper :stick to be moved downwardly for crowdingthedipper '33 beneathmaterial to be loaded therei'n while the dipper stick is pivotedcounter-clockwise =for advancing the dipper outwardly with a scoopingSuch pivotal movement of the dipper.

stick is accomplished by winding the cable 29 upon the drum 3| asexplained 'hereinabove.

In Fig. 2 the boom I4 is illustrated at 'a60 degree angle of inclinationwith respect to .the horizontal while in Fig. 3 it is shown at a '30degree angle and in Fig. 4 it is shown in the horizontal position. Asexplained hereinabove the inclination angle of the boom is controlled bya hoist cable l9, and it is the function of the additional belt guidemeans 62 and 66 to so control the relative lengths of the belt spansrespectively between the guide means 6Z66 and said guide means 41 thatduring pivotal movement of the boom I4 about the axis in the footmg pinIS the ends of these spans atthe guide-means "41 will co-describesubstantially an are having Til its point not generation coincident withth 1111"!Sdidi8h8ifi? l6. Suchnregulation of the belt spans respectivelybetween the guide means equal radial .distances from said pin. The guidemeans 82 and 65 are also arranged upon substantially diametricallyopposite sides of the pin 1-6 and in .zclOse proximity therewith. Withthis arrangement .of the belt guide :means 62 and :66 "the sprocketstherein will. roll along their reispectiveibelt portions ,inoppositedirections when the boom is pivoted and'the effective rolling distancesof said sprockets will be substantially equal. For example, if twopoints A and B are arbitrarily-chosen upon the belt portions .35 and.

64 as shown in Figs. 2,3 and 4 and the points A and B are determinedupon these belt portions at the points of tangency of the aforesaid beltspans (disposed between the belt guide means 62-:66 and the belt guidemeans 41) when the boom is in the degree position shown in Fig. 2, andif tangential points A" and B" are determined upon these belt portionslike the determination of the points A and B but when the boom is in the30 degree position and if tangential points A and B' are similarlydetermined .whenthe :beam is "in the horizontal, the following table=will-express the functional relation of distances traversed by thesprockets in the belt guide means 62 and :66 along. their respectivebelt 1 portions:

AA plus BB quals C AA" plus BB" equals C AA' plus B equals C where Cisa-constant.

It will be seen therefore when the boom I4 3 horizontal position in Fig.4 the guide means 52 in rolling along the retrieving belt portion 35will tend to shorten the span between this belt guide means and the beltguide means 41,-

but, concurrently, the belt guide means 66 will be rolling backwardlyupon the crowd belt portion 54 and thereby tend to lengthen the spanextending along the beam from this guide means to the guide means 41.Meanwhile as the beam l4 lowers, the guide means 41 will be rotated bythe belt portions 35 and 64, counter-clockwise as viewed in Fig. 1,while taking up the increment of belt span payed out by the belt guidemeans 156 and while paying out into the span of the belt portion 35enough of such belt portion to compensate for the shortening effect ofthis span by the forwardly advanced guide means 52. Because of thisrotation of the guide means .47 the dipper stick 26 will be elevatedrelatively to the boom. This however is of'no substantial consequencesince the operator can readily adjust the dipper stick to the desiredheight by manipulating the controls for causing rotation of thereversing means 63 in the proper direction. When the hoisting cable I9is taken in upon the drum 2B for raising the boom M from the horizontaltoward the position shown in Fig. 2 the belt guide means 62 and 66 willbe moved in the opposite direction along their respective belt portions,thereby causing the guide means 4? to rotate slightly clockwise wherebythe dipper stick will be moved endwise downwardly, but again theoperator can readily adjust the dipper stick to the desired axialposition by manipulation of said controls for causing the reversingdrive means 63 to rotate in the desired direction.

It will be seen therefore that I have provided a boom structure in whichthe crowd belt is expediently operable in either direction for reversingendwise movement of a dipper stickand that the arrangement of the crowdbelt is such that it interferes in no way with the raising and loweringof the boom. In this way the machine is made so readily manipulatablethat frequent readjustment of the boom to the most advantageouselevation is practicable.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent that various changes may be made in the form, construction andarrangement of the parts without departing from the spirit and scope ofthe invention or sacrificing all of its material advantages, the formhereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In a boom structure having a boom pivotal about a transverse axisintersecting its footing, and a work member movable in oppositedirections on saidboom; means for effecting such movement of the workmember, comprising belt guide means on the boom at a position spacedaxially thereof from said footing and for rotation about a single axis,second belt guide means disposed adjacent the part of said footingintersected by said footing axis, belt portions connected with said workmember at respective positions removed oppositely from said first beltguide means and extending to and circumferentially about such guidemeans in opposite directions and thence lengthwise of the boom to andabout respective of said second belt'guide means, and means connectedwith sections of the belt portions reaching beyond said second beltguide means and operable to pull in either of said belt portions whilepaying out the other.

2. In a boom structure having a boom pivotal about a transverse axisintersecting its footing, and a work member movable in oppositedirections on said boom; means for effecting such movement of the workmember, comprising belt guide means on the boom at a position spacedaxially thereof from said footing and rotatable about a single axissubstantially parallel with the footing axis, second belt guide meansdisposed adjacent the footing at respective positions spacedtransversely of the boom and upon opposite sides of said footing axis,belt portions connected with said work member at respective positionsremoved oppositely from said first belt guide means and extending to andcircumferentially about such guide means in opposite directions andthence lengthwise of the boom to and about respective of said secondbelt guide means,

and means connected with sections of the belt portions reaching beyondsaid second belt guide means and operable to pull in either of said beltportions while paying out the other.

3. In a boom structure having a boom pivotal about a transverse axisintersecting its footing, and a work member movable in oppositedirections on said boom; means for effecting such movement of the workmember, comprising belt guide means on the boom at a position spacedaxially thereof from said footing and rotatable about a single axissubstantially parallel with the footing axis, second belt guide meansdisposed upon said boom adjacent the part of the footing intersected bysaid footing axis, said second belt guide means being at respectivepositions spaced transversely of the boom and upon opposite sides ofsaid footing axis, belt portions connected with the work member atrespective positions removed oppositely from said first belt guide meansand extending to and circumferentially about such guide means inopposite directions and thence lengthwise of the boom to and aboutrespective of said second belt guide means, and means connected withsections of the belt portions reaching beyond said second belt guidemeans and operable to pull in either of said belt portions while payingout the other.

4. In a boom structure having a boom pivotal about a transverse axisintersecting its footing, and a work member movable "in oppositedirections on said boom; means for effecting such movement of the workmember, comprising belt guide means upon an intermediate portion of theboom and rotatable about a single axis, belt drive means disposed in aposition removed from alignment with said belt guide means and the partof the footing intersected by said footing axis, belt portions connectedwith said work member at respective positions removed oppositely fromsaid belt guide means and extending to and circumferentially about saidguide means in opposite directions, one of said belt portions includingcomponents spaced axially of said rotatable guide means on the boom andbetween which the other belt portion is disposed upon said guide means,said belt portions extending in flights from said guide means to saidbelt drive means, and second guide means for said flights and disposedadjacently to and respectively above and below the part of the boomfooting intersected by said footing axis, said flights being displacedlaterally respectively about said second guide means to provide, in eachof said flights, a span running generally axially of the boom betweenits associated second guide means and said first named guide means, andsaid second guide means being so spaced radially of the footing axisthat the parts of the belt flights contiguous therewith are spacedsubstantially equally from the footing axis and the relative positionsof said second guide means circumferentially of said axis being suchthat the ends of said spans, when moved with said first named guidemeans about said footing axis, will describe substantially an aregenerated about such footing axis.

5. In a boom structure having a boom pivotal about a transverse axisintersecting the footing and projecting generally forwardly from saidfooting, a dipper stick having upper and lower ends and movable endwisein said boom, and a dipper upon the lower end of said dipper stick;means for efiecting such endwise movement of the dipper stick,comprising belt guide means upon an intermediate portion of the boom ad-'jacently to said stick and rotatable about a single axis substantiallyparallel with the footing axis, reversible belt drive means disposedrearwardly of said footing and out of alignment with said belt guidemeans and the axis-intersected part of said footing, a crowding beltportion comprising laterally spaced components connected with an upperend section of the dipper stick and extending downwardly thereof to andcircumferentially about said guide means in one direction and thence asa flight to said belt drive means, a retrieving belt portion connectedwith a lower end section of said stick and extending upwardly to andabout said guide means in the opposite direction at a section betweensaid belt components and thence as a flight to said drive means, andsecond belt guide means respectively for said flights and disposedadjacently to and respectively above and below said footing axis, saidretrieving belt flight being displaced downwardly about the upper secondguide means and said crowding belt flight being displaced downwardlyabout the lower second guide means-whereby said second guide meanseffect spans in said flights running generally axially of the boom tosaid first named guide means, and said second guide means being sospaced radially of the footing axis that the parts of the belt flightscontiguous therewith are spaced substantially equally from such axis andthe relative positions of said second guide means circumferentially ofsaid footing axis being such that the ends of said spans, when movedwith said first named guide means about said footing axis, will describesubstantially an arc generated about such axis.

HILBERT E. SWANSON.

